


Curious Case

by FKAErinElric



Category: Sherlock (TV), Supernatural
Genre: Case Fic, Castiel using Sherlock as vessel, Gen, Holmes family part of British Men of Letters, Men of Letters
Language: English
Status: In-Progress
Published: 2019-03-18
Updated: 2019-03-18
Packaged: 2019-11-23 21:30:24
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,144
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18157265
Author URL: https://archiveofourown.org/users/FKAErinElric/pseuds/FKAErinElric
Summary: After an incident Castiel loses his vessel and finds one in London named Sherlock Holmes.Now Sherlock and John find themselves helping Sam and Dean; the game is afoot!





	Curious Case

**Author's Note:**

> My first crossover :D
> 
> This idea came to me after watching Sherlock yesterday. I was a little gun shy about writing it but decided to throw caution to the wind and go for it. 
> 
> Takes place in Series 2 of Sherlock and roughly season 8 of Supernatural

 

            Sherlock was in the midst of playing his violin. He focused on the music, on the string instrument in his hand. He and John had been working on a case, a case that seemed to be leading nowhere. He had sent John out to get some fish and chips at his favorite eatery while he studied the situation some more. He paused his playing and stared at the photos hanging on the board in front of him. There was a missing man; one Jacob Cox who just seemed to have vanished out of thin air. CCTV footage showed him walking down the side walk and suddenly Mr. Cox was gone. He stared at the photos of the footage. Did the man slip in a building? Did a person in a passing car manage to snatch him in a blind spot? He let out an annoyed sound and went back to his violin.

            Suddenly there was an ear piercing sound. “Ugh!” He cried out, and covered his ears. Violin and bow still in hand he covered his ears the best he could. He looked around the room looking for the source of the noise. Was it an attack? Was it the radio? He noticed the radio was on and with a frown he marched over to it and shut it off. The sound stopped. He shook his head and looked at his violin his ears were still ringing. He wondered what sort of interference that was when the radio came back on again.

            He stared at it taken back by it suddenly coming on. He studied it for a minute. Was there something wrong with the radio? Was someone remotely turning it on? He reached out for it when he heard a voice come from it.

            “Help me.”

            He’s hand hesitated above the off switch. He looked around the room; he was defiantly alone in the flat. “Hello?” He asked out loud. Maybe he was losing his mind.

            “Help me.” The voice was definitely coming from the radio

            He thought maybe he was picking up someone on a broadcast sending out a message for help. He frowned he couldn’t very well answer this person but maybe he could figure out where they were. He listened closer and the shrill noise came through again. He cried out and covered his ears. He heard glass shatter around him as he fell to his knees.

            “I need a vessel.” The voice said

            The voice cracked in and out along with the shrill noise. Sherlock feared he would go deaf and he needed all of his senses for his detective work. “What do you need from me?” He demanded.

            “Say yes, I’ll give it back shortly.”

            He wasn’t sure he completely understood but he had to make the noise stop. “Yes!” He shouted. Suddenly the noise stopped and the flat was filled with a bright light.

 

 

            John Watson let out an annoyed sigh as he opened the door to 221 B. He balanced the food in his arms as he ascended the stairs to his shared flat. He looked at Miss Hudson’s door and kept heading up. Much to his surprise it was quiet. He figured he would hear Sherlock stomping around up there, or playing the violin or shooting up the wall something. He opened the door. “I’m back Sherlock.” He announced as he came in. His shoes crunched broken glass and he looked down. “The hell happened here?” He looked at all the broken glass from the beakers of his science kit; a mirror was shattered as well. “Sherlock what on Earth where you doing?” He asked as he sat down the food on the table. Sherlock was faced away from him and staring out the window or at least what was left of the window. “Oh man Miss Hudson is going to be upset over this one.” He looked at his friend who still didn’t move. “Sherlock you alright?” He crossed the floor over to his friend and he laid his hand on his shoulder.

            The taller man looked over at him. His expression was blank as he looked at him.

            “Sherlock?” He asked again. He could see there was something wrong with the other man. Panic rose up in his mind. What had happened to him? He looked over him, he couldn’t see anything wrong with him immediately but Sherlock was off.

            He tilted his head and squinted his eyes. It was a facial expression he had never seen him do before. “Sherlock?” He asked. John noticed how his voice was deeper than before. He tilted his head again. “Oh yes, that is this vessel’s name.” He stated coldly.

            John backed away. “What the bloody hell is going on?” He demanded. He wouldn’t admit it but he was a little bit freaked out by Sherlock’s strange behavior, and he was already a strange guy.

            He stood there and looked at John as if studying him. “I am not Sherlock.”

            He blinked. “Not Sherlock?” Was there something medically wrong with Sherlock? “Look maybe we should get you to a hospital.”

            He kept staring at him. He started walking forward and John kept moving away from him. “What state am I in? I need to find Dean and Sam.”

            “S-state?” John stammered as he backed into a wall. “You’re in London. Don’t you remember Sherlock?”

            Sherlock frowned. “Is this not America?” He looked around the flat then back at John. “Oh I see I am in London I didn’t notice before.”

            John blinked. Sherlock wasn’t acting like Sherlock it was almost like he had a second personality. He was pretty sure if he did he would have noticed already. He had been living with the man for a while now. “W-who are you?” He asked. He knew after watching him for the last few minutes whoever he was talking to was not Sherlock Holmes.

            “I am Castiel Angel of the Lord.”

            He felt like he got hit by a truck. “Wait did you say angel? You are trying to tell me you are an angel?”

            He nodded. “It is the truth. I needed a new vessel. There was a fight and I got ejected from my other vessel. I needed a new one and… I found this one.” He looked down at his own body and tilted his head again. “I asked and he gave permission to use his body.”

            “Sherlock is letting you use his body?” He asked. He was so confused. Was this real? Or was he dreaming?

            He nodded again. “I need to get to America I have to get my other vessel and help Sam and Dean.” He picked up his black coat and put it on. He studied the material then eased on a scarf.

            “Are you going to just catch a plane to America? And what about-“John’s questions were cut off when suddenly Sherlock (er well Castiel) grabbed him. It felt like the wind was whirled around him and then poof he was no longer in the flat. “About Sherlock?” The question left his lips and he realized they were in a field. “Where are we? What?” He’s brain couldn’t wrap around what had happened.

            “I flew us to America.” Castiel stated. He was rummaging in the pockets of the coat and frowned the whole time.

            “You flew us… holy shit you aren’t lying are you really an angel?” He felt his voice tighten. There was an actual bloody angel in Sherlock!

            “Yes I am an angel.” He stated sounding annoyed. He frowned at the coat. “Does this vessel have a cellular device?”

            He blinked. “Oh a cell phone? Ugh it was probably on the table. Sherlock rarely keeps it on his person in the flat he considers it a distraction.” He pulled out his phone. “But you can use mine.” He unlocked it and the angel took it. “Do you know how to use it?” He asked skeptical

            He pressed a few buttons. “I can access my vessel’s memories for most human tasks…” He held the phone up to his ear. “Dean?”

            John listened and could hear someone talking on the other line. Definitely an American.

            “It’s Castiel, no I found another vessel. Yes I know it’s British.” He rolled his eyes. “Well where are you?” He nodded and then said. “Okay I’ll see you there.” He handed the phone back to John. “They are at the bunker.” He stated flatly.

            “Bunker? Is that supposed to mean something to me?”

            He looked around. “Right now we are in Kansas. The bunker is in Lebanon Kansas and…” He started forward and reached out to John.

            John flinched when he figured he was about to teleported again but Castiel stopped short of reaching him. “You alright?”

            The angel stood there for a second then frowned. He’s eyes rolled up in the back of his head and he crumbled to the ground.

            “Sherlock!” John cried. He tried to catch his friend as he fell. He grabbed his arm and was almost pulled down with him. He quickly checked his pulse, no sooner than his fingers touched his wrists the detective bolted up right.

            “Where am I?” He looked around his eyes wide and frantic. His voice was back to its normal baritone tone.

            “Sherlock is that you?”

            He looked at John. “Of course it’s me.” He stated. “Where are we John?”

            “Kansas.”

            “What? We are in America? How did we get here?” He looked around again and shook his head.

            “Do you not remember?”

            Sherlock looked at him and John decided to continue talking.

            “I went out to get food and when I came back I found all the glass broken and you were acting weird. You told me your name was Castiel and you were an Angel of the Lord and you needed to get back to America to help some guys named Sam and Dean… and you well he had lost his body. At least I assume it’s a he…” He mumbled the last part. “The angel flew us here and he called his friends on my phone and he said they were at a bunker.”

            “Bunker? He said they were at a bunker?”

            He shot him a dirty look. “Of all the craziness I just listed off what gets your attention is the word bunker?” He shook his head. “Listen if it wasn’t for the sudden trip to America I would think we were both off our rocker but… there is something clearly going on.”

            “Bunker.” Sherlock mumbled again. He started walking away and John followed him shouting at him to stop. “Bunker.” He repeated. He had heard of it before. Stories told among the family whispers of people called the Men of Letters and they stayed in a bunker. He brought his hands to a point and rested his chin on them as he walked. The Men of Letters… they did research on monsters wasn’t that the story? But monsters weren’t real right? No such thing just some nonsense made up for television and movies. Then again… after hearing John’s story he could vaguely remember the situation in the flat with the shrill noise and the voice from the radio. Sherlock would be lying if he said he felt alone in his body. He shuttered. There was someone else in his mind and he didn’t think he liked the idea.

            _“What are you doing?”_

            He stopped and looked at John who finally caught up with him. “I’m going to find this bunker.”

            John frowned. “I asked if you were feeling okay.”

            He went to answer when he heard.

            _“I didn’t expect this to happen. I have never had a human take back over…”_

            Sherlock looked at John who was staring at him. “I don’t know… I think I’m hearing a voice.”

            “A voice?”

            He nodded and there it was again.

            _“Sherlock I need to return to Sam and Dean please. I will give you back your body once my vessel is found.”_

“Where is your vessel? Maybe I can help you find it?”

            “Who are you talking to?” John asked worry clear in his voice

            Sherlock gestured to his head. “Castiel apparently, he really wants to see those people.”

            _“We need to go to the bunker. I don’t doubt that you can help find my old vessel but you are not equipped to deal with the situation.”_

            Sherlock chuckled. “I can deal with any situation you toss at us.”

            _“Please, let me take us to the bunker.”_

“Fine.”

            John’s jaw almost hit the floor when he seen Sherlock’s eyes suddenly glow in a bright blue light. “What the-“

            Sherlock (no Castiel) turned to him and held out his hand. “Come on let’s go.” He’s voice was deeper again and his expression was blank. He grabbed John who let out a scream as the world whooshed around him again.


End file.
